SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '714a71fda92c422ddc6d999e74934c47a7cf488bd1b9dbac831c0bfba223a182' 
  AND token = 'EFLAgkBbWlTKRhEYoJGPk0LTsBvFumObPPj5FCfw8oc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}